There are four muscle tendons that connect to the shoulder that make up the rotator cuff. Together these four tendons stabilize the upper arm bone to the shoulder socket and allow the wide range of motion in the shoulder.
Update Date 8/12/2013
Updated by: C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.